Lady Loretta Mine advances its progressive rehabilitation

Glencore’s Lady Loretta Mine is continuing to advance its progressive rehabilitation ahead of the sites’ planned completion of mining operations in 2025.

A key part of the rehabilitation process is the construction of a modern engineered waste rock emplacement facility, which has been in the works since 2012. 

The purpose of the facility is to manage reactive potential acid forming rock and mineral waste, which is produced by the mining operations.

Potential acid forming rock is common in metals mining. When the metals and rock, which are high in sulfide minerals, are exposed to oxidising conditions such as water and air, the rock has the potential to produce sulfuric acid, also known as acid mine drainage.

The biggest concern surrounding the potential acid forming rock and subsequent acid mine drainage is that it has the ability to contaminate the surrounding environment, and in particular, natural water supplies if it is not managed and contained correctly.

Lady Loretta Senior Environmental Advisor, Joe Kaspar, says the facility separates clean and contaminated water and contains the potential acid mine drainage.

“The facility has been constructed with a low permeability foundation and drainage infrastructure that directs contaminated water (including the acid mine drainage) to a lined containment dam,” says Joe.

“Additionally, upstream of the facility, drains have been constructed to divert clean water away from the facility as much as possible to prevent the unnecessary contamination of clean water.”

“Further, in 2022 we consolidated historic acid forming waste stockpiles which means that only one waste rock emplacement facility will require rehabilitation.”

“Current upgrades to the emplacement facility have also made the progressive installation of a permanent cover system possible.”

“An updated closure options analysis was also recently undertaken for the waste rock emplacement, and included a detailed analysis of the various options to determine the optimal final landform cover and was supported by findings from studies undertaken at our other operations.”

“A Bituminous Geomembrane (BGM) cover was determined to be preferred for the crest, due to the reactive nature of the waste rock and the optimal level of protection it provides below the rock/soil cover, particularly in wet/dry environments.”

“This preferred cover helps to provide chemical and physical stabilisation of the waste material in the storage facility.”

The Lady Loretta Mine team is dedicated to minimising environmental impacts from the mining operations and these progressive rehabilitation works allow them to restore the mined land to an agreed state after closure.

Following the post closure period, the Lady Loretta site is proposed to be used for native vegetation habitat as well as grazing land.